Julie, here from Shopify Support.
Based on your question, it sounds like you will need to adjust your inventory settings to prevent overselling when a product is sold out. Luckily, you can use bulk actions in your Shopify Admin to save you from having to edit the inventory settings for each individual product. To do this, simply head over to Products in your Admin and select the items you'd wish to edit. Then, select Actions > Edit products > Add fields > Continue selling when out of stock. You'll now see checkboxes next to each product. To prevent selling products that aren't in stock, simply uncheck these boxes.
Now, there are a couple of different ways to correct this particular order. Are you needing to refund the customer and cancel this order, then create a new one? If so, we have some instructions on how to refund and cancel orders that will walk you through the process on how to do so. When issuing a refund, you also have the ability to restock the product, which will bring your inventory levels back to an accurate number. Issuing a refund isn't necessary if you'd like to simply exchange the product. If this is the case, then you can issue a refund for $0, while still restocking the product.
Once this refund is processed, you can then create a manual order with a different product. If you'd like to charge the customer for this order, you can email them an invoice with a link to pay. Alternatively, if you chose not to refund the customer and would like to simply offer a straight exchange, you can add a 100% discount to the order and the customer will not need to process a payment.
However, if you are still able to fulfill this order and would like to simply adjust the inventory quantity on this product for future orders, we have a help doc on adjusting inventory I recommend checking out here. This help doc explains how you can manually adjust the inventory quantity for a particular product. It also explains how inventory tracking works and how you can view the inventory history of a certain product.
Let me know if you have any further questions.
You're correct - while there is a notification in the app, it can often be overlooked. Having a more noticeable notification, like a sound or popup would definitely help prevent overselling using the Shopify POS.
Receiving feedback from merchants like yourself allows us to continue improving our platform, introducing new features to best suit the needs of our merchants. I think this is a fantastic suggestion and although you have brought this up with our teams before, I will also be sending this up to our developers; the more feedback, the better.
Overselling in POS and in Draft Order is a large issue for numerous people in the Shopify community. I am somewhat shocked that Shopify hasn't made any progress towards giving their customers the option to turn off overselling. I have been looking for a way to fix this and have come across post after post asking for this same functionality going back years, and nothing has been done. Please provide that feedback to your development team.
First off, I appreciate your feedback. I can completely understand the need to prevent overselling with the POS and draft orders and can see how this would be a very useful feature. We actually have a system in place for providing feedback and feature requests to our developers and I can see that this is something that quite a few merchants have requested. I'll make sure to add your name to the list of those looking for this feature; the more feedback we get, the better.
Thank you for your suggestion! If you need anything else, please don't hesitate to reach out.
I'm having the same issue, it's so frustrating. We launched our store yesterday, and nearly have of the sales were double sold items. We're a small thrift store, and almost always have only 1 of something. We had to refund 4 of 10 sales yesterday due to double sales. I'd appreciate any help on this!